Intentional modification of the optical spectral response and relative sensitivity of luminescent thermometers based on Fe³⁺,Cr³⁺,Nd³⁺ co-doped garnet nanocrystals by crystal field strength optimization

Abstract

The relative sensitivity and usable temperature range of Fe3+,Cr3+-based luminescent thermometers can be tuned by modification of the crystal field strength.

Defect Enrichment in Near Inverse Spinel Configuration to Enhance the Persistent Luminescence of Fe3+

“…[45] PL decay curve of the representative MGO:Fe 3+ sample shows a double-exponential decay with an effective PL lifetime of 9.374 ms, which is similar to the previously reported value of other Fe 3+ -doped compounds (Figure 2b). [38] After removing the UV light, MGO:Fe 3+ exhibits intense PersL, as shown in Figure 2c and Figure S5, Supporting Information. To the best of our knowledge, this is the first report for the investigation of PersL properties by utilizing Fe 3+ as an effective activator in MGO host.…”

“…[35,36] Hitherto, the majority of the research concerning Fe 3+ -activated luminescent materials is devoted to their photoluminescence (PL) properties and the related luminescence thermometer application. [37,38] This may be because Fe 3+ is usually regarded as a luminescent quencher, and it is hard to control the crystal environments of the matrixes for achieving PersL of Fe 3+ . Therefore, it is vital importance to explore a special crystal structure and regulate the defect properties for the development of Fe 3+ -activated NIR PersL materials.Spinel configuration can be one of the best host material candidates when designing PersL materials owing to the easy formation of vacancies and anti-site defects.…”

Synergy between NIR luminescence and thermal emission toward highly sensitive NIR operating emissive thermometry

“…Due to low scattering and absorption of the light by the tissue, near infrared (NIR) spectral range, where optical transparency windows of tissues occur, is especially desirable to report temperature dependent spectral signatures. Up to date many different phosphors have been proposed as NIR emitting noncontact temperature sensors including: quantum dots [17][18][19] , silicon nanoparticles 20 , nanogels 21 , inorganic nanoparticles doped with lanthanide ions [22][23][24][25][26][27][28] or transition metal ions [29][30][31][32][33][34] , nanodiamonds 35 , metal-organic frameworks 36 , coordination polymers 37 , semiconductor nanoparticles 38 etc. The progress in luminescence based thermometry, is strongly related to the advancement in available materials, especially because low intensity NIR emission of the phosphors inevitably increases the uncertainty of the temperature determination.…”

Deep red upconversion photoluminescence in Er3+‐doped Yb3Ga5O12 nanocrystalline garnet

“…Garnets doped with RE and/or TM ions are intensively studied for fluorescence 13 or persistent luminescence 14 generated via anti‐Stokes (upconversion) or Stokes processes 15 . In contrast to microcrystalline garnets, prepared by direct synthesis, the nanocrystalline garnets with high surface‐to‐volume ratio may be utilized as contrast agents in bioimaging, 16 sensors and detectors, 17,18 high‐resolution displays, 19 emergency signage, 20 and solid‐state lasers 21 . Upconversion photoluminescence (UCPL) emission with emission color tunability in nanocrystalline garnets is a subject of many studies 22–24 .…”